Encyonema nicafei

S.A.Spauld. 2010      Category: Asymmetrical biraphid

REPORTED AS: Cymbella muelleri ((Patrick and Reimer 1975, pl.7, fig. 1)) | Encyonema sinicum ((Krammer 1997, figs 44-55)) 

Encyonema neogracile


Encyonema norvegicum

LM scalebar = 10 µm = 40 pixels.


Contributor: Sarah Spaulding - April 2010
Length Range: 56-76 µm
Width Range: 16.5-19 µm
Striae in 10 µm: 9


Valves are strongly dorsi-ventral. The dorsal margin is narrowly arched, while the ventral margin is linear. Valve length is 56-76 μm; breadth is 16.5-19 μm. The valve apices are broadly rounded. The axial area is relatively broad in the central part and an oval area is expanded towards the dorsal margin, narrowing at the valve ends. The raphe branches have a slight arch towards the ventral margin. Each raphe branch is positioned nearly centrally within the axial area. Proximal raphe ends are slightly expanded and dorsally deflected. Distal raphe ends curve slightly to the dorsal margin, but are deflected ventrally near the valve apices. The dorsal striae are slightly divergent. Externally, the rows of dorsal areolae closest to the central area are oval, and become lineolate, or apically elongate. Dorsally, central striae number 9 in 10 μm and distal striae number 5-6 in 5 μm. Ventrally, central striae 7 in 10 μm, and distal striae 6 in 5 μm. The density of areolae within a central, dorsal stria is 9 in 5 μm.

Original Description

Author: S.A.Spauld. 2010
Length Range: 56-76 µm
Width Range: 16.5-19 µm
Striae in 10 µm: 9

Original Description

Valvulae sunt valde dorsiventrales. Dorsualis margo anguste arcuata est, sed ventralis margo linearis est. Valvulae longitudo 56-76 μm est; amplitudo 16.5-19 μm est. Valvulae terminationes roundatus late. Axialis superficies est relative ampla in centrali valvula et ovalis extrinsecus. Suturae ramificationes levem habent arcum ad ventralem marginem. Unaquaeque suturae ramificatio posita est fere centrali positione intra axialem superficiem. Suturae extrema proxima leviter sunt expansi et dorsualiter deflexi. Suturae extrema distalia suturae curvaminis leviter inflectuntur marginem ad dorsualem, sed ventraliter sunt deflexa prope valvulae apices. Dorsuales striae sunt in diversum leviter. Externe, primae series sunt ovales fiuntque lineolatae, maiorque fit lineolatarum longitudo ad dorsualem marginem. Dorsualiter, striae numeris 9 sunt in 10 μm; centraliter sunt 7 in 10 μm.

Original Images

Original text and images reproduced with permission by Academy of Natural Sciences of Philadelphia.

Cite This Page:
Spaulding, S. (2010). Encyonema nicafei. In Diatoms of the United States. Retrieved April 22, 2018, from http://westerndiatoms.colorado.edu/taxa/species/encyonema_nicafei

Species: Encyonema nicafei

Contributor: Sarah Spaulding

Reviewer: Mark Edlund


Spaulding, S.A., Pool, J., Castro, S. and Hinz, F. (2010). Species within the genus Encyonema Kützing, including two new species Encyonema reimeri sp. nov. and E. nicafei sp. nov. and E. stoermeri nom. nov., stat. nov. Proceedings of the Academy of Natural Sciences of Philadelphia 160(1):57-71. 10.1635/053.160.0107

Links & ID's

Index Nominum Algarum (INA)

California Academy of Sciences (CAS)

North American Diatom Ecological Database (NADED)


Autecology Discussion